This invention relates to tufting machines and more particularly to a method and apparatus for producing heretofore unknown patterning effects in the pile fabric produced, such patterning being provided by periodically selectively changing the spacing between tufts in the same longitudinal row of stitching.
In the production of tufted fabrics a plurality of spaced yarn carrying needles extend transversely across the machine and are reciprocated cyclically to penetrate and insert loops of yarn into a backing material fed longitudinally beneath the needles. The loops are seized by loopers or hooks oscillating below the fabric in timed relationship with the needles as the loopers or hooks cross the needles just above the needle eye. In loop pile machines the loopers point in the direction in which the backing material is being fed, hold the seized loops while the needles are being retracted from the backing, and thereafter move away from the point of seizure to release the loop. In cut pile machines the hooks point in the direction opposite to the direction in which the backing material is being fed so the loops feed onto the hooks and each hook cooperates with a respective oscillating knife. Since the loops are being fed toward the closed end of the hook they cannot be released except by being cut by the knife. As the hook rocks away from the point of loop seizure the knife rocks upwardly and cuts the loop. During each penetration of the backing material a row of pile is produced transversely across the backing material. Successive penetrations result in a longitudinal row of pile produced by each needle.
This basic method of tufting limits the aesthetic appearance of tufted fabrics so produced. Thus, the prior art has developed a number of procedures for creating various pattern effects.
One such procedure is to vary the amount of yarn fed to the individual needles selectively. By varying the amount of yarn fed to the individual needles high and low loops can be selectively produced. The most widely used apparatus for producing variations in pile height in tufted fabrics is a yarn feed roller attachment wherein feed rollers are selectively driven at one of a plurality of different speeds controlled by a pattern control. Representative of such feed roller patterning are the disclosures in Card U.S. Pat. No. 2,862,465; Card U.S. Pat. No. 2,966,866; Hammel U.S. Pat. No. 3,103,187; Singleton U.S. Pat. No. 3,489,326; Short U.S. Pat. No. 3,605,660; Hammel U.S. Pat. No. 3,847,098; Lear et al U.S. Pat. No. 3,926,132 and Prichard et al U.S. Pat. No. 3,955,514.
Another procedure for patterning in a tufting machine is to form spaced rows of cut pile and loop pile. A number of methods have been devised to perform this patterning. For example, in Card U.S. Pat. No. 3,084,645; Jolley et al U.S. Pat. No. 4,134,347; Inman U.S. Pat. No. 4,185,569 and Ingram et al U.S. Pat. No. 4,301,752 cut pile and loop pile may be formed selectively in the same row of stitching by various means such as back robbing yarn to move a spring clip away from a hook which has seized a loop of yarn, the loops withdrawn remaining uncut while those not withdrawn are cut by a knife acting in conjuntion with the hook. In others of these patents level cut pile and loop pile may be formed in the same row of stitching by controllably moving a gate which opens and closes passage of a loop onto the hook. In Card et al U.S. Pat. No. 3,919,953 adjacent rows of loopers and hooks point in the opposite direction to each other to form alternate rows of cut pile and loop pile.
Another procedure for pattterning is to initiate relative lateral movement between the backing material and the needles to laterally displace longitudinal rows of stitching. One method is to jog or shift the needle bar transversely across the tufting machine relative to the base material in a step-wise manner in accordance with a pattern. Bryant et al U.S. Pat. No. 3,026,830; Smith U.S. Pat. No. 3,964,408; Smith U.S. Pat. No. 3,972,295; Webb U.S. Pat. No. 4,010,700; Schmidt et al U.S. Pat. No. 4,173,193; and Ingram U.S. Pat. No. 4,392,440 are exemplary of this prior art. Another method of initiating such relative movement is by jogging or shifting the needle plate which effects movememt of the backing material. Exemplary of this prior art are Card U.S. Pat. No. 3,301,205; Watkins U.S. Pat. No. 3,577,943; Smith U.S. Pat. No. 3,934,524 and Ingram et al U.S. Pat. No. 3,964,407. A third method of initiating such relative lateral shifting is by use of what is known as a "jute shifter" whereby the backing material is shifted by a spike roller laterally of the tufting machine.
The great popularity of tufted broadloom carpeting has, in fact, been due to these various patterning developments. At one time woven broadloom accounted for substantially all of the carpeting produced, and due to the nature of that process the goods were expensive and affordable only to a relatively few. Today because of the developments in the tufting art, tufted broadloom accounts for approximately 95% of the market, and because of the faster production rates and lesser amounts of yarn required, tufted carpeting is readily available to the great mass of the population. Recently, tufting has made inroads into the upholstery field with developments in very fine gauge tufting machines and with the ability to form very low pile. However, the typical broadloom patterns are not generally appealable aesthetically for upholstery fabric and weaving is still by far the major process for producing such goods.